• Pancreatic transplantation is hampered by difficulties in controlling exocrine drainage. Methods of controlling exocrine drainage were assessed in 30 dogs receiving right lobe pancreatectomy. In the sham group, laparotomy and dissection of the pancreas were performed. In the others, the duct was either left open, ligated, anastomosed to jejunal mucosa, or injected with 1.5 mL of either silicone rubber, Neoprene, or Prolamine. Serial serum glucose and amylase levels were obtained at regular intervals and pancreatic biopsies were performed at two and eight weeks for examination. Glucose homeostasis was maintained throughout the study period. All animals developed severe pancreatitis as shown by hyperamylasemia by the second postoperative day, which resolved in most animals by the tenth to 14th day. Animals were free of ascites, pancreatic abscesses, and pseudocysts. All methods of ductal obstruction as well as the open duct drainage led to islet and acinar fragmentation and fibrosis. Endocrine function was preserved in all groups. In three animals with patent ductaljejunal anastomoses, the pancreas appeared normal. Duct-to-jejunum anastomosis was the preferred method to preserve pancreatic function and morphology. (Arch Surg 1985;120:1132-1137)